1. Field of the Invention
The invention relates to a remaining life determining system for estimating the remaining life of a stationary storage battery obtained by recycling a battery used in a vehicle, or the like, and a method of determining the remaining life of the stationary storage battery.
2. Description of Related Art
A power storage device that supplies electric power to a motor for running a vehicle is installed on an electric vehicle, or a hybrid vehicle. The power storage device deteriorates due to repeated charge and discharge. A method of assessing the remaining life of the power storage device is disclosed in, for example, Japanese Patent Application Publication No. 2011-64571 (JP 2011-64571 A). According to the method, the usage state of a dead battery as a battery that has reached the end of its life, and dead-battery charging characteristics as charging characteristics of the dead battery when it is charged according to a predetermined charging sequence, are associated with each other and stored into information storage means for storing information, and the usage state of a battery to be assessed (which will be called “test battery”), and test charging characteristics as charging characteristics of the test battery when it is charged according to the predetermined charging sequence, are obtained. Then, the remaining life of the test battery is assessed or determined from the relationship between the obtained test charging characteristics, and corresponding dead-battery charging characteristics as the dead-battery charging characteristics associated with the usage state of the dead battery corresponding to the obtained usage state of the test battery, as a part of the information stored in the information storage means.
FIG. 6 schematically illustrates the database structure of estimated information obtained by estimating chronological changes of a vehicle battery. In a hybrid vehicle, for example, the current value of the vehicle battery changes from moment to moment, due to changes in running conditions, etc., resulting in a large number of charge/discharge patterns. Therefore, a large number of remaining life maps used for determining the remaining life of the vehicle battery need be prepared in accordance with the number of the charge/discharge patterns.